Small difference in MIME headers

barry's Avatar


09 Jul, 2017 06:49 PM

I'm coming from Claws Mail on Ubuntu which also supports encryption and signing. I noticed something slightly different when sending an email via GPGMail rather than Claws. I'm using OpenPGP in both cases.

I've noticed that GPGMail adds a Content-Disposition header to the signature attachment that specifies a filename. When you view this with some mail readers (e.g. Claws), it shows up as a little bit of extra clickable text in the body of the message. Clicking on that lets you save the attachment, etc. This might be considered unnecessary since that bit already has a Content-Type header that correctly identifies the attachment. Claws does not include the Content-Disposition header so you don't get that (very minor! :) annoying clickable text.

It might be nice to be able to control whether the Content-Type: application/pgp-signature block gets a Content-Disposition header or not. I haven't actually verified whether that's required by the standard or not (in which case, CM is out of standard, and never mind! :).

Very minor request for an otherwise great tool!

  1. Support Staff 1 Posted by Luke Le on 10 Jul, 2017 02:24 PM

    Luke Le's Avatar

    Hi Barry,

    thank you very much, we really appreciate that you like are tool.
    I've looked it up, and the PGP/MIME RFC doesn't seem to require the signature part to be an attachment or have any filename or name set either.
    We would have to test, if any of the popular plugins, Enigmail especially, would have problems if we were to remove the Content-Disposition: attachment part.

    Thanks for your input, we've created a ticket for this issue.

  2. 2 Posted by barry on 10 Jul, 2017 02:41 PM

    barry's Avatar

    On Jul 10, 2017, at 02:24 PM, Luke Le wrote:

    Sounds great Luke, thanks! I'm happy to test between my various MUAs.


  3. Steve closed this discussion on 10 Jul, 2017 02:55 PM.

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